Effects of Electroacupuncture at Back-shu and Front-mu Points on Expression of GDNF in Colon Tissue of Functional Constipation Mice

OBJECTIVE To explore the mechanism of electroacupuncture at Back-shu and Front-mu points for functional constipation treatment. METHODS 32 mice were randomly divided into control group， model group， electroacupuncture (EA) group and EGC group. Compound diphenoxylate were gavaged for modeling， and electroacupuncture Tianshu and Dachangshu points， 30 min each time for a total of 5 times treatment. By light microscopy， electron microscopy， immunohistochemistry and in situ hybridization， the morphology of colonic epithelial structure were observed， and the level of GDNF protein and mRNA expression in colon were detected. RESULTS The expression of GDNF protein and mRNA in model group was significantly decreased (P<0.01). Electroacupuncture at back-Shu and front-Mu points improved the expression of GDNF protein and mRNA (P<0.05)， and light microscope and electron microscope showed that acupuncture repaired damaged depithelial cells， and then improved the intestinal transmission function. The expression of GDNF protein in EGC group showed no significant difference with the model group (P>0.05)， but significantly decreased， compared with EA group (P<0.05). GDNF mRNA was significantly higher than model group (P<0.05)， but lower than EA group with no significant difference (P>0.05). The morphology change of colon tissue is more serious. CONCLUSION Electroacupuncture at back-Shu and front-Mu points can improve the expression of GDNF protein and mRNA in EGC cells， repair the colonic epithelial cells， and then improve the intestinal transmission function.